Agricultural combines are well known in the art for harvesting and threshing various agricultural crops, including for example, wheat, soybeans, corn, etc. Usually, agricultural combines include a harvesting apparatus, an infeed mechanism, a separating or threshing apparatus, and a cleaning apparatus. In operation, the harvesting apparatus reaps the crop, which is planted in the ground. After reaping, the infeed mechanism feeds the crop to the separating or threshing apparatus.
Typically, the separating apparatus in a rotary combine includes at least one rotor, which can extend axially (front to rear) or transversely within the body of the combine, and which is surrounded at least in part by a perforated concave having a plurality of apertures. The grain is threshed and separated by the separating apparatus, and the separated grain, together with some impurities, such as chaff, dust, and crop residue particles, are fed to a cleaning system to clean the impurities from the grain. Clean grain is collected below the cleaning system and fed to a grain tank for temporary storage. The clean grain, impurities and smaller elements and particles of the crop residue are separated form the bulk of the crop residue by the separating apparatus and the resulting residue is delivered for processing by a discharge delivery system.
While the terms “grain” and “crop residue” are used principally throughout this specification for convenience, it should be understood that these terms are not intended to be limiting. Thus “grain” refers to that part of the crop which is threshed and separated from the discardable part of the crop material (e.g. straw), which is referred to as “crop residue”.
Discharge delivery systems rely on a device such as a discharge beater or straw walker, to propel or convey the separated crop residue rearwardly within a body of the combine to a residue handling system. Generally, straw walkers, which involve crank mechanisms for conveying the crop residue rearwardly through a combine, are relatively slow in operation and thus have a limited material handling capability or rate. The crank mechanisms add complexity and vibration. Discharge beaters “throw” or propel the crop residue away from the separator and toward the rear of the combine. In both instances, the crop residue can be discharged discharged directly in its raw form through a rear opening of the combine onto the harvested field; it can be directed into a chopper mechanism in connection with the rear of the combine which chops the crop residue and then discharges it onto the harvested field; or the chopper can function just as a spreader for spreading the unchopped crop residue onto the field.
Today's new, improved combines have greater harvesting and threshing capacities. Although discharge systems such as briefly discussed above have also improved, the harvesting and threshing systems of modern combines can at times produce volumes of crop residue material that can exceed the capacity of the discharge systems, leading to plugging thereof and packing of crop residue thereagainst and over the cleaning system, which can require substantial down time and effort to remove. In some instances, the only warning of plugging is when an operator notices that crop residue is no longer being discharged or is being discharged at a rate which appears to be too low or the pattern of discharge is incorrect. For instance, in this latter regard, if one side of the crop flow path to the chopper is plugged, the corresponding portion of a swath of a field over which the chopped residue is to be spread or distributed may be covered with less residue compared to the opposite side, which may be unsatisfactory. Therefore, it would be advantageous if accurate early warning or information indicative of onset of a plugging condition were provided, to allow an operator or automatic control to take steps to avoid further or increased plugging, such as decreasing the combine ground speed to reduce the crop material throughput so as to clear the condition, and avoid more extensive plugging and the down time and effort to remove it.
As an additional problem, crop residue directed toward a plugged or partially plugged chopper can be deflected onto a chaff handling system of the combine, if present, so as to interfere with the proper operation thereof and its effectiveness, thereby also resulting in combine down time, decreases in harvesting productivity, and increases in operator and owner dissatisfaction and component failure. Therefore, it would be advantageous to avoid this problem also.
Accordingly, what is sought is a system or method for detecting a plugging of a crop residue chopper of a combine, and particularly the onset of such plugging, which provides one or more advantages, and overcomes one or more problems, set forth above.